if (typeof Crypto == "undefined" || !Crypto.util) {
    (function () {

        var base64map = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

// Global Crypto object
// with browser window or with node module
        var Crypto = (typeof window === 'undefined') ? exports.Crypto = {} : window.Crypto = {};

// Crypto utilities
        var util = Crypto.util = {

            // Bit-wise rotate left
            rotl: function (n, b) {
                return (n << b) | (n >>> (32 - b));
            },

            // Bit-wise rotate right
            rotr: function (n, b) {
                return (n << (32 - b)) | (n >>> b);
            },

            // Swap big-endian to little-endian and vice versa
            endian: function (n) {

                // If number given, swap endian
                if (n.constructor == Number) {
                    return util.rotl(n, 8) & 0x00FF00FF |
                        util.rotl(n, 24) & 0xFF00FF00;
                }

                // Else, assume array and swap all items
                for (var i = 0; i < n.length; i++)
                    n[i] = util.endian(n[i]);
                return n;

            },

            // Generate an array of any length of random bytes
            randomBytes: function (n) {
                for (var bytes = []; n > 0; n--)
                    bytes.push(Math.floor(Math.random() * 256));
                return bytes;
            },

            // Convert a byte array to big-endian 32-bit words
            bytesToWords: function (bytes) {
                for (var words = [], i = 0, b = 0; i < bytes.length; i++, b += 8)
                    words[b >>> 5] |= (bytes[i] & 0xFF) << (24 - b % 32);
                return words;
            },

            // Convert big-endian 32-bit words to a byte array
            wordsToBytes: function (words) {
                for (var bytes = [], b = 0; b < words.length * 32; b += 8)
                    bytes.push((words[b >>> 5] >>> (24 - b % 32)) & 0xFF);
                return bytes;
            },

            // Convert a byte array to a hex string
            bytesToHex: function (bytes) {
                for (var hex = [], i = 0; i < bytes.length; i++) {
                    hex.push((bytes[i] >>> 4).toString(16));
                    hex.push((bytes[i] & 0xF).toString(16));
                }
                return hex.join("");
            },

            // Convert a hex string to a byte array
            hexToBytes: function (hex) {
                for (var bytes = [], c = 0; c < hex.length; c += 2)
                    bytes.push(parseInt(hex.substr(c, 2), 16));
                return bytes;
            },

            // Convert a byte array to a base-64 string
            bytesToBase64: function (bytes) {

                // Use browser-native function if it exists
                if (typeof btoa == "function") return btoa(Binary.bytesToString(bytes));

                for (var base64 = [], i = 0; i < bytes.length; i += 3) {
                    var triplet = (bytes[i] << 16) | (bytes[i + 1] << 8) | bytes[i + 2];
                    for (var j = 0; j < 4; j++) {
                        if (i * 8 + j * 6 <= bytes.length * 8)
                            base64.push(base64map.charAt((triplet >>> 6 * (3 - j)) & 0x3F));
                        else base64.push("=");
                    }
                }

                return base64.join("");

            },

            // Convert a base-64 string to a byte array
            base64ToBytes: function (base64) {

                // Use browser-native function if it exists
                if (typeof atob == "function") return Binary.stringToBytes(atob(base64));

                // Remove non-base-64 characters
                base64 = base64.replace(/[^A-Z0-9+\/]/ig, "");

                for (var bytes = [], i = 0, imod4 = 0; i < base64.length; imod4 = ++i % 4) {
                    if (imod4 == 0) continue;
                    bytes.push(((base64map.indexOf(base64.charAt(i - 1)) & (Math.pow(2, -2 * imod4 + 8) - 1)) << (imod4 * 2)) |
                        (base64map.indexOf(base64.charAt(i)) >>> (6 - imod4 * 2)));
                }

                return bytes;

            }

        };

// Crypto character encodings
        var charenc = Crypto.charenc = {};

// UTF-8 encoding
        var UTF8 = charenc.UTF8 = {

            // Convert a string to a byte array
            stringToBytes: function (str) {
                return Binary.stringToBytes(unescape(encodeURIComponent(str)));
            },

            // Convert a byte array to a string
            bytesToString: function (bytes) {
                return decodeURIComponent(escape(Binary.bytesToString(bytes)));
            }

        };

// Binary encoding
        var Binary = charenc.Binary = {

            // Convert a string to a byte array
            stringToBytes: function (str) {
                for (var bytes = [], i = 0; i < str.length; i++)
                    bytes.push(str.charCodeAt(i) & 0xFF);
                return bytes;
            },

            // Convert a byte array to a string
            bytesToString: function (bytes) {
                for (var str = [], i = 0; i < bytes.length; i++)
                    str.push(String.fromCharCode(bytes[i]));
                return str.join("");
            }

        };

    })();
}
